The technique of measuring eye movements utilizing infrared light emitters and detectors placed in front of the eye is well known in the prior art. Typical arrangements of emitters and detectors include the use of imaging devices such as one- and two-dimensional charge coupled devices (CCD), and symmetrically arranged photodetectors such as photodiodes and phototransistors. The drawbacks of using CCD detectors primarily lie in cost as well as strict mechanical placement requirements, whereas the use of photodectors reduces cost and complexity of the device. The symmetrical arrangements specified in the prior art while simplifies the reduction of data, however may require the construction of devices that interfere with an operators eyebrow or nose.
The use of gaze location for computer cursor control is a key technology component that will enable users to interact with computer in a hands-free fashion. Cybemet Systems has successfully utilized video oculography eye tracking techniques to localize an operator's gaze for computer control. Drawbacks of this approach include the cost and complexity of the requisite components: video camera, frame grabber board, and dedicated personal computer to perform the image processing. Additionally, the placement of a video camera into the optical path of a head/helmet mounted display (HMD) presents significant integration challenge as well as increasing the size and weight of the head/helmet mounted components.